Dr. Rogers Tycos SphygmomanometerOscar Harrison Rogers, MDTaylor Instrument Companyca. early-mid 20th centuryDr. Roger's Tycos Sphygmomanometer in leather-covered case, with a cloth storage bag included. On the dial, beneath the name of the instrument, gives a manufacturing number of 87400, and a patent date (and pending) of December 21, 1915.still image